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E. T. GREENFIELD. ELECTRIC vSWITGH.

No. 477,409. Patented June 21, 1892.

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awww/woz wilma/Q@ UNITED STATES PATENT OEEicE.

EDXVIN T. GREENFIELD, OF NEWT-YORK, N. Y., ASSIGNOR TO THE IN'TRIORCONDUIT'AND INSULATION COMPANY, OF SAME PLACE.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 477,409, dated June 21,1892. Appiicafionfiiednecemha16,1891. `seria No. 415,253. Numan To a/ZZwhom t may concern.-

Be it known that I, EDWIN T, GEEENEIELD,

a citizen ofthe United States, residing at New York, in the county of-New York and State of New York, have made a new and useful Invention inElectrical Switches or Circuit Making and Breaking Devices, of which thefollowing is a specification.

My invention is directed particularly to a lo novel device forpreventing what is known as arcing7 between the electrodes of a switchdesigned to carry large-quantity or high-tension currents-such, forexample, as is used in electric lighting and analogous electrical I5systems.

For a full, clear, and exact understanding of theinvention here claimedreference is had tothe following specification, taken in connection withthe accompanying drawings, in all of which like letters of referenceindicate like or analogous parts wherever used.

Figure l of the drawings is a transverse sectional view of a well-knownform of two-pole snap-acting switch having my improvement attached, thecircuit being shown as closed, while Fig. 2 is a similar view showingthe circuit open. Fig. 3 is a side or elevational view of the sameswitch with the cover partly broken away to better illustrate theinterior construction thereof and to show, also, my improvement inconnection therewith. Fig. 4 is a side elevational view of a well-knownforni of jackknife-switchwith my improvement attached; and Fig. 5 is atransverse sectional view of the same, taken through the operative partsthereof.

It is a well-known fact that where a circuit carrying a large-quantitycurrent or a current of high potential is ruptured there appears at thepoint of rupture an arc, which in course of time as the circuit is manytimes broken will seriously impair the electrodes. Numerous devices havebeen utilized for overcoming or preventing this are. To illustrate,currents or puits of air have been forced upon the electrodes, therebyblowing out the are. Magnets, both permanent and electro, have beenutilized for drawing it aside and rupturing it. The electrodes have beenimmersed in oil, water, or alcohol with a view of extinguishing the arc.These and other methods,

all more or less successful, have been utilized; but no one, so far as Iain aware, has ever resorted to a positive means of disrupting the areby injecting a spring-actuated are intereepter or snui'fer between snapor spring acting electrodes which suddenly rupture a circuit, and myimprovement is of this general nature.

I will now describe my improvementin de- 6o tail. B represents the baseof a snap-switch, made, preferably, of porcelain, and O the coverthereof. h I) and b o are binding posts or screws secured to the base,adapted one pair to receive the wires w w on one side and the other pairto receive the corresponding wires on the other side. S S and S S' arethe snap-acting contact-springs,secured one pair to the posts h l) andthe other pair to the posts b h', said springs being double-leafed attheir 7o free ends, the inner leat` of each pair being turned outward,as shown. E is the switchshaft, pivotally secured to the base B andprovided with an operating-handle H. D is a revolving ratchet-blocksecured to the shaft E and held in place by a transverse pin j). All ofthe parts so far described are well known in the art and constitute,when assembled, what is known as a hand-switch, in which the circuit isopen between the springs S S 8o on one side and S S on the other whentheir free ends lie in the notches of the ratchetblock D in the positionshown in Fig. 2 and is closed when the ends of said springs are incontact, as shown in Fig. l.

My improvement consists in providing a pair of are interiupters orsnuffers A A of insulating material-such as vegetable fiber, glass, orthe like-and preferably wedgeshaped and of a width greater than thewidth 9o ofthe springs, said parts being attached to the free ends ofsprings t t, secured in turn to the binding-posts l) and h or to anypart of the switch box or base. The springs t t are preferably in thenature of corrugated strips, as shown, and their normal tendency is toforce the interrupters or snuters inward toward the free ends of theinner springs S and S, thereby intercepting the arc. rllie mode ofoperation is obvious, it being linden loo stood that at the instant thefree ends of the inner springs S S drop oil the ledges or ratchets ofthe insulating ratchet-block D the interrupters or snuiers will beforcibly thrust forward, thereby snufling out or intercepting the are. Ifind that with such an arrangement the arc is effectually disrupted.

Fig. 4 illustrates the application of my improvement to jackknife-switches, K bein g the jackknife, pivoted at P in the usualmanner and adapted to contact at its free end between theelectrode-plates P P2. In this instance the interrupters or snuiTers A Aare attached to the free ends of the springs t t, which in turn aresecured to the electrodeplates P P2. Vhen the blade K is drawn upward,the interrupters or snuffel-s A A are forced together into the path ofthe arc and it is snuled out. If preferred, the snuiers A A may becarried by the blade K.

I do not limit myself to the specific apparatus herein shown anddescribed for effectually snuiing or wiping out an arc between positiveor snap-acting electrodes, as I believe I am entitled to claim, broadly,the combination of one or more pairs of spring-actuated or otherpositive snap-acting` electrodes with instantaneous or positive springactuated snufiing devices adapted to be inserted between the electrodesat the instant that they are separated by such positive snap action.

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States, is-

l. A pair of snap-acting` electrodes, in combination with aspringactuated arc-interrupter of insulatingmaterial for interccptinfl,ran arc established between said electrodes, substantially as described.

2. A switch provided with one or more pairs of snap-acting electrodes,in combination with a spring-actuated arc-interrupter of insulatingmaterial for each pair of electrodes.

3. A switch, a pair of spring-actuated electrodes, with their free endsresting normally on a ratchet-block made of insulating` matcrial, incombination with a spring-actuated arc-interrupter of insulatingmaterial, substantially as described.

et. A switch provided with two pairs of spring` actuated electrodes anda ratchetblock secured to an operating-handle, in co|nbination withspring-actuated arc-interrupters of insulating material adapted to passbetween the ends of the electrodes and disrupt the are7 substantially asdescribed.

EDWIN T. GREENFIEL'D. lVitncsses:

EDWARD F. SEIXAs, CHAS. J. KINTNER.

